So...here's how my day went...
The correct cables for v3 targets came in, so I set about to install them. Did not go so great at first.
The old targets and the new targets mounting bracket are not shaped the same. The new ones are not 90 degree, they are angled up at about 85 and have longer lips. This caused the targets by the reverse ramp to be pushed against the front of the holes so they were always activated. I think they did this trying to angle the targets slightly down toward the pf so that the back plate would be less likely to bend (and they do indeed bend...all of my originals are bent pretty far).
I ended up having to swap the new brackets with the old brackets for that ramp. There were other minor issues with the new targets that prevented me from installing them so I only did the airlock and reverse ramp targets..which, honestly is fine. Those are the ones that get the most action. The new backplates seem to be slightly thicker than the old ones, so we'll see if they bend over time --- but really...this target design is just not a good design to hold up to repeated impacts. They need to move away from it if they make future games.
So then I turn it on to test and everything works except the LCD. I fudge with all the cables and try again. This time I'm watching the LCD. It does indeed come on, until the PC posts, and then nothing. So I spent another 10 minutes tracing and figiting with cables until it finally comes on, but when it comes on, the right half of the game doesn't work (but not the same as if a fuse blew). Checked fuses all good. Booted another 3-4 times with same result. Figit with cables again, and finally right side comes on, but LCD doesn't come on again. SMH. I get into this alternating issue of if the monitor works, the right side is out and vice versa....and then...for no apparent reason everything starts working. I turned it on and off a few more times, and played a few games with no further issues, so I seal it up and put it back in place (slowly as to not shake any cables). Played for another hour with no issues.
I know this is going to be an issue later....I'm just not sure why.